Centralized patient monitoring systems have been in use for a number of years. These systems are typically used in an intensive care unit (ICU), but are not limited to such use. A typical patient monitoring system includes a bedside monitor for each patient. The bedside monitor includes transducers for monitoring physiological parameters such as ECG, heart rate, blood pressure and any other parameters that may be important for a specific patient. The bedside monitors are connected to a central station that is located, for example, at a nurse station. The patient information gathered by the bedside monitors is displayed at the central station on a video display screen. The video display screen is typically divided into sectors, or areas, and patient information from one bedside monitor is displayed in each area. For example, the screen may contain four, six or eight sectors. The patient information displayed in each sector of the screen may include demographic information, such as name, bed number and ID number or physician, and physiological parameters being monitored by the bedside monitor. Typically, at least one of the physiological parameters is a waveform.
The patient monitoring system also has the ability to handle patient critical events, or alarms. For example, when one of the physiological parameters being monitored meets a predetermined alarm criteria, an alarm is generated by the bedside monitor and is transmitted to the central station. The alarm can be annunciated at the central station in various ways. According to one technique, an alarm text is displayed in the corresponding sector of the video display screen, and a small area surrounding the alarm text is highlighted in a alarm color. In addition, an audible alarm is generated by the central station. Alarms are typically classified into several categories. For example, a "red" alarm may indicate a life threatening patient condition, a "yellow" alarm may indicate a serious but non life threatening patient condition, and a "green" alarm may indicate an equipment malfunction.
It will be understood that it is extremely important to present the information on the video display screen of a patient monitoring system in a clear and unambiguous manner. When any confusion or misunderstanding occurs, the ability to respond to patient conditions quickly may be compromised. Thus, it is important that alarm conditions be clearly annunciated on the video display screen. The alarm condition should not obscure or detract from other patient information that is being displayed. Furthermore, the alarm condition should not be confused with other less serious alarms or with alarms which have already been attended to and acknowledged. The alarm condition should be visible from a distance, since the users of the system do not always sit directly in front of the video display screen.
Prior art systems have had various disadvantages with respect to the above requirements. For example, in the above described system, the alarm indication (including an alarm text on a small colored background) remains on the video display screen as long as the condition which gave rise to the alarm exists, even though a nurse may have attended to the patient. Thus, several alarm conditions may appear on the screen simultaneously. Some of the alarms may require attention, while others may have been attended to. The audible tone generated by the central station indicates only the highest level of alarm, not the number of such alarms or whether alarms of lower priority exist. Thus, there is the possibility of confusion as to which alarms, if any, require service and which alarms have been serviced.
One known technique for highlighting critical events is to cause an alarm indication or critical physiological parameter to flash. A flashing condition is very effective in attracting the attention of the user. However, the flashing condition may be so attention getting that it detracts from other important information being displayed on the screen. Furthermore, when several items simultaneously flash on the screen, confusion may arise. Another known technique for annunciating alarm conditions is to replace all or part of the multiple patient display with an enlarged display pertaining to the alarm condition. While this approach is clearly effective in highlighting the alarm condition, it obscures information pertaining to other patients and is not effective when more than one alarm condition exists simultaneously.
It is thus desired to provide a technique for displaying patient information on a video display screen wherein alarm conditions are clearly annunciated without obscuring other patient information. The display must indicate which alarm conditions have been attended to and which alarm conditions require attention. The display must also indicate the severity of the alarm and must indicate alarm conditions from a distance.
It is a general object of the present invention to provide improved methods and apparatus for displaying patient information and patient critical events in a centralized monitoring system.
It is another object of the present invention to provide centralized patient monitoring methods and apparatus wherein patient critical events are clearly highlighted until acknowledged by a user.
It is a further object of the present invention to provide centralized patient monitoring methods and apparatus wherein patient critical events are highlighted in a color that is easily distinguishable from colors used under normal conditions and which does not obscure patient information.
It is yet another object of the present invention to provide centralized patient monitoring methods and apparatus wherein patient critical events are highlighted in a manner that is easily identified from a distance.
It is a further object of the present invention to provide methods and apparatus for clearly presenting patient information and patient critical events on a video display screen in a centralized patient monitoring system.